Shuttle thrower for sewing machines



1962 A. MORO 3,064,605

SHUTTLE THROWER FOR SEWING MACHINES Filed April 16, 1959 8 lnvenlor 4/v7'0w/0 M02 YJWMM Attorney United States Patent 3,064,6h Patented Nov. 23, 1952 Free 3,064,605 SHUTTLE 'I'HROWER FQR SEWING MACHINES Antonio Moro, Milan, Italy, assignor to S.p.A. Fratelh Borletti, Milan, Italy Filed Apr. 16, 1959, Ser. No. 806,866 Claims priority, application Italy May 7, 1958 3 Claims. (Cl. 112-232) In sewing machines with oscillating shuttle a known way of reducing the objectionable noisiness, particularly at high speed, of the impulses that the thrower imparts to the shuttle at the start of its movement, is to provide the thrower on its inner side with a leaf spring due to which the impulses are applied resiliently.

However, with the provision of such a spring there is the danger of restricting the opening for the issuance of the needle thread, at the corresponding end of the thrower, in such a way that the thread is blocked or impeded in its passage across the said opening.

The elimination of this disadvantage is the object of the improved shuttle thrower which forms the subject of the present invention.

The said thrower, provided with a leaf spring on its internal surface, is characterised by the feature that between the sector member which constitutes it and the spring applied thereto there is interposed, at a certain distance from the end of the spring that faces the opening for the issuance of the needle thread, a deformable prominence which keeps the spring out of contact with the body of the thrower and which, after the installation thereof in the sewing machine, is capable of being flattened in such manner as to cause the spring to approach the said body so as to adjust the opening between the thrower and the shuttle in the required manner without the need for additional adjustment.

In a preferred construction the said prominence is constituted by an internally hollow calotte-shaped protuberance, preferably hemispherical, presented by the spring or by the body of the thrower and, in either case, either integral with said spring or said body, or carried by a member fixed to the said spring or body.

The spring which is fixed to the body of the thrower by means of at least one screw, can be in one piece or in two pieces and can also be limited to the part in which the prominence is interposed between the spring and the body of the shuttle thrower.

An example of the subject of the invention is illustrated in the accompanying drawing, in which:

FIG. 1 represents the assembly of the thrower and the shuttle in front view;

FIG. 2 shows the details, on a larger scale than FIG. 1, of the prominence between the body of the thrower and the spring, before adjustment;

PEG. 3 illustrates the same detail when adjustment has been effected and FIG. 4 shows the details, on a larger scale than FIG. 1, between the other end of the spring and the body of the thrower.

Reference numeral 1 indicates the sector-shaped thrower, which oscillates as shown by the arrows 2, under the control of a mechanism of known type, in the sewing machine, along a predetermined are. This are is necessary and sufiicient to enable the shuttle 3, shifted by the thrower, to insert its point 4 in the loop of the upper thread formed by the needle (not shown) and to allow the thread to issue continuously from the opening 5 when the assembly has completed the return phase of the alternating cycle.

On the body 1 of the thrower is mounted, by means of screws 6, the leaf spring 7 which shows end 11 bent around the end 8 of the thrower 1 and the other end 9 extends with a slight survature over the other end 10.

Ends 9 and 11 constitute driving ends of the thrower 1.

The bent end 11 touches the shuttle 3 at part 14 under the point 4, and the end 9 touches the other part 12 of the shuttle. The movements of the thrower 1 thus shift the shuttle 3 in an alternating manner, the shuttle being held in a suitable guide 16, the said movements being transmitted via the driving ends 9 and 11 of the spring '7 which by reason of its considerable resilience softens the impulses applied by the thrower to the impulse-receiving parts 12 and 14 of shuttle 3 and substantially eliminates the noise of the impulses.

The arrangement so far described may be regarded as known in general. The characteristic feature of the invention resides in the fact that the end 9 of the spring does not touch the end 10 of the thrower but is held a short distance away from it by a hemispherical calotteshaped protuberance 13, which is hollow internally and is formed in the spring '7 by stamping. The arrangement is such that when first assembled the end 9 of the spring 7 and the end 12 of the shuttle are in contact, and like-wise the end 11 of the spring is in contact with the other contact place 14 of the shuttle, under the point of the said shuttle.

Under such conditions the needle thread cannot pass, or does so only with difliculty.

Now, however, the protuberance 13 becomes effective; by flattening the spring, according to the arrows 15, with pliers or a suitable tool, in the zone of the protuberance 13 against the internal surface of the end 1%, the protuberance itself is deformed, or the material of the end 10 is deformed at the point of contact, and consequently the point 9 moves away from the end 12 in such a manner as to space the end 9 from the end 12 suitably, as can be seen for example in FIG. 3. There is left the width 5 required for the passage of the thread, without however the end 9 making firm contact with 10, but still allowing it a short resilient movement which serves to soften the impulses.

The details of the arrangement can be varied from those illustrated in the drawing and described above, without exceeding the scope of the invention; and indeed some possible variations have already been indicated in the introductory part of the present specification.

What I claim is:

1. A shuttle mechanism for a sewing machine comprising an oscillatory shuttle provided with arcuately spaced impulse-receiving surfaces, an oscillatory sectorshaped shuttle thrower having an inner surface and spaced driving ends for engaging the impulse-receiving surfaces, a leaf spring mounted on the inner surface of the thrower with one end thereof bent around one end of the thrower in spaced relation thereto to engage and cushion impact with one of the impulse-receiving surfaces of the shuttle and the other end of the spring partially bent over the other end of the thrower to engage the other impulse-receiving surface, and a deformable protuberance between the thrower and the spring adjcent the partially bent end of said spring spacing said partially bent end of the spring away from the other end of the thrower to engage said other impulse-receiving surface, said protuberance being deformable by a tool to adjust the position of the partially bent end of the spring to provide a thread clearance between it and said other impulse-receiving surface of the shuttle.

2. A shuttle mechanism for a sewing machine comprising an oscillatory shuttle provided with arcuately spaced impulse-receiving surfaces, an oscillatory sectorshaped shuttle thrower having an inner surface and spaced driving ends for engaging the impulse-receiving surfaces, a leaf spring mounted on the inner surface of the thrower with one end thereof bent around one end of the thrower in spaced relation thereto to engage and cushion impact with one of the impulse-receiving surfaces of the shuttle and the other end of the spring partially bent over the other end of the thrower to engage the other impulse-receiving surface, and a deformable protuberance on the "spring adjacent said partially bent end thereof spacing said partially bent end of the spring away from the other end of the thrower to engagesaid other impulse-receiving surface, said protuberance being deformable by a tool to adjust the position of the partially bent end of the spring to provide a thread clearance between it and said other impulse-receiving surface of the shuttle.

3. A shuttle mechanism according to claim 1, in which the protuberance is hollow chl' shaped.

References Cited in the file of this patent JVood Nov. '9, 1937 Sie'br'asse Apr. 10, 1956 Ayres May 27, 1958 FOREIGN PATENTS 

